1. Field of the Invention
The present invention relates to a lace tightening apparatus useful more particularly for a shoe, for example, and in particular, a sports shoe.
2. Description of Background and Relevant Information
Lace tightening apparatus include hooking and/or guidance elements for the lace which are affixed, respectively, on the two portions that are to be brought together and/or tightened towards one another. The hooking and/or guidance elements define a lacing plane. These hooking and/or guidance elements are constituted by eyelets, loops, rivets, guides, grommets, etc. which are distributed along the length of the edges of the two portions to be laced.
In known lace tightening apparatus, the hooking and/or guidance elements of the lace define an opening for passage of the lace which is either contained in the lacing plane or is perpendicular to this plane. In the first case, when the openings of the hooking and/or guidance elements, such as eyelets, are contained in the lacing plane, the lace passes alternately above and beneath the successive eyelets. Such lace tightening apparatus are described, for example, in the following patents: British Pat. No. 771,703; U.S. Pat. No. 1,434,723; German Pat. No. 3,323,170; and French Pat. No. 2,586,343. With these lace tightening apparatus in which the passage of the lace is alternated through the successive hooking and/or guidance elements, relatively high friction of the lace on the hooking elements and on the portions to be tightened will occur (e.g., a tongue of a shoe which is covered by the two portions before being tightened). This causes an irregular tightening which is most often insufficient at the beginning of the lacing.
In the case where the passage openings of the lace in the successive hooking and/or guidance elements extend in planes perpendicular to the lacing plane, the lace passes flat through the openings. Such lace tightening apparatus are described, for example, in German Pat. No. 497,455; Swiss Pat. No. 403,563; and French Pat. No. 1,307,133. In these lace tightening apparatus the design of the hooking elements is relatively complex and when these elements are constituted by hooks, a sure maintenance of the lace in place when the lace is loosened is not guaranteed.